(1) Field of the Invention
The present invention relates to a control member provided firstly with a lever for controlling the collective pitch of blades of a rotorcraft lift rotor, and secondly with yaw control means for controlling the yaw movement of the aircraft. The invention also provides an aircraft provided with such a control member.
The invention lies in the field of rotorcraft, and more particularly in the field of control means for directional piloting of the rotorcraft in yaw.
(2) Description of Related Art
A rotorcraft has a rotary wing. The rotary wing has at least one lift rotor with a plurality of blades. The lift rotor thus participates in providing the aircraft with lift, and possibly also with propulsion if the rotorcraft is a helicopter, for example.
Furthermore, the rotorcraft may include a device for controlling the yaw movement of the rotorcraft. Depending on the rotorcraft, the yaw movement control device may be implemented by means of an additional rotor, by means of at least one propulsive propeller, or indeed by means of a device for ejecting fluid, for example.
Under such circumstances, the rotorcraft has a plurality of control means that can be operated by a pilot in order to pilot the rotorcraft. The pilot then moves the control means in order to generate control orders. These control orders thus give rise to a maneuver or the rotary wing and/or of the yaw movement control device.
The control orders may be transmitted mechanically or electrically, in particular to servo-controls in order to modify the pitch of blades in a rotating assembly.
In order to control a lift rotor, the control means may for example be connected to servo-controls that move a set of plates known as “swashplates”. These plates then comprise a non-rotary plate connected to the servo-controls and a rotary plate connected to each of the blades of a lift rotor.
The rotorcraft can then have a collective pitch control member acting on the collective pitch of the blades of the rotary wing, and a cyclic control member acting on the cyclic pitch of the blades of that rotary wing.
The collective pitch control member usually comprises a lever suitable for performing pivoting movement in a substantially vertical plane. The collective pitch control member is thus known as the “collective pitch lever”.
The cyclic pitch control member usually comprises a stick suitable for performing turning movement about two axes. The cyclic pitch control member is thus sometimes referred to as a “cyclic stick”.
In addition, a rotorcraft may include a yaw control member of the pedals type for controlling the rotorcraft in yaw via the yaw movement control device. For example, the pedals may control the collective pitch of blades of an additional rotor.
Such pedals are advantageous, but they present the drawback of obstructing a pilot's field of view when looking downwards and forwards.
In addition, the pedals may give to ergonomic problems associated with the size of a pilot.
Likewise, the pedals may give to ergonomic problems associated with a limiting height of a control panel above the pedals. A pilot's knees run the risk of hitting such control panel when the pilot seeks to move the pedals with the feet.
Finally, the use of pedals can require the pilot to make an intellectual effort in order to avoid issuing a yaw control going in the direction opposite to the desired direction.
In the state of the art, document FR 2 479 133 proposes a control system having four piloting axes for controlling collective pitch, cyclic pitch about a longitudinal axis, cyclic pitch about a transverse axis, and yaw movement.
Document U.S. Pat. No. 5,395,077 proposes replacing pedals with a control joystick. The joystick has its base fastened to a hinge with two perpendicular axes. The joystick can then perform pivoting movement in a vertical plane about a first axis in order to transmit a collective pitch control order, and in a horizontal plane about the second axis in order to transmit a yaw movement control order.
Document U.S. Pat. No. 4,819,896 suggests arranging a turnable handle on a cyclic control stick.
Document US 2004/0130529 describes a device having a lever that extends in elevation from a support towards a handle.
Also known is document JP 2009 073355.